Model Output Discussion - heading into April

[johnholmes]

I'll have to disagree mb, the chart you show is GFS synoptic, less reliable than the 500 mb anomaly charts for the 6-14 day time frame. If you look at the 8-14 it still has a noticeable contour ridge along with some +ve heights. Over the years it is almost always a lesser looking ridge where the 6-10 is more marked. Sometimes the 6-10 turns out nearer the mark, and the chart I was trying to show about a week ago (6-10) had a similar ridge to the issue from last evening. Not sure where I posted it but it is somewhere on the site-sorry can't show it.

Anyway whichever of us is nearer the mark no problem, each is entitled to their view. It is only weather anyway, fascinating to follow what the different models suggest may happen even 5 days ahead let alone 10.

Just to add the anomaly NOAA 6-10 first started to suggest an upper ridge around 7 April and has been pretty consistent since.

[MATTWOLVES 3]

What's occurring folks. So we have a bit of a blip this next couple of days with an increasing risk of showery rain, and temps somewhat suppressed. The exception to the rule being the far North of the UK, where it looks to remain drier and brighter throughout. A gradual improvement come Sunday, with the best of the brightness towards the West. Things look to improve further as we go through next week, with good sunny spells and temps nudging up towards above average in the West with shelter, always a bit more prone to cloud and cooler conditions towards the East Coast. Overall it is certainly of benefit to the extension of another 3 weeks of lockdown, so make sure you get out and soak a bit of it up.... It can at least benefit your mental health.. 

I'm off for the weekly shop, where my mental health will take a battering now... I just don't do crowds, and other idiots walking past you like the 2 metre rule doesn't exist... Stay safe all. 

Edited April 17, 2020 by Mattwolves

[Frosty.]

Looking at the Gfs 6z operational the T-Storm risk increases later today, tonight and into tomorrow across the s / se but most of the u k stays fine with sunny / clear spells and then further ahead, most of the coming week we are under high pressure with plenty of sunshine and light winds (breezy / windy further s / sw for a time)..beyond that, a few bumps in the road but higher pressure predominantly having the upper hand!

 

Edited April 17, 2020 by JON SNOW

[Zak M]

Yes, next week is certainly looking like high pressure will dominate our weather again!

   

The GFS shows something a bit unsettled from day 11 onwards to day 15

   

And it shows another high perhaps creeping in from the Atlantic into the start of May

   

Obviously the two charts above have a less than 10% chance of verifying, but next week once again looks like a beautiful week, with temperatures in the south creeping into the high teens! A very dry and warm April it has been so far!

[Methuselah]

The GEFS 06Z temperature ensembles look rather good too:

    

[Frosty.]

Looking through the GEFS 6z P20 would be rather nice for early May!

[Methuselah]

According to the GFS 12Z, Monday has 'stonker' written all over it!

    

[Geordiesnow]

8 minutes ago, General Cluster said:

According to the GFS 12Z, Monday has 'stonker' written all over it!

    

Very gusty though so the feel of things will be tempered somewhat. Hints are the winds should ease down going into Tuesday but then after that is anyone's guess as tonight's UKMO12Z run shows. 

West is best in these set ups though especially in terms of warmth. 

[Methuselah]

Okay, I know it's at T+384 (and about as likely to verify as one of George Osborne's ill-fated National Debt 'forecasts') but it'd be nae bad, if it did become reality?

    

[Methuselah]

And, once again, the GEFS temperature ensembles aren't that bad:

    

[mb018538]

Bit breezy to start the week, but it looks like  another rip snorter for April. Dry, lots of sunshine, and warm for many (except the east coast). End of the week looks even better with light winds and warm air holding on.

[Singularity]

I must say, it’s been quite something to watch the model output adjust away from Greenland height rises when we’re not even in winter...!

Next week’s actually starting to look warm again by Thursday, possibly sooner, as the broad ridge gradually relaxes fully across the UK, such that the cool easterly breeze drops out for most.

Depending on how cool the nights are, this could place April in the top ten for mean temp. Max temp could finish top-5, maybe even top-3?

[Portsmouth Sun]

3 hours ago, General Cluster said:

According to the GFS 12Z, Monday has 'stonker' written all over it!

    

If you like an Easterly gale it’s fab. It will feel very chilly in East Anglia.  The next week looks like being dry and increasingly warm away from North Sea coasts.

[Methuselah]

2 minutes ago, Portsmouth Sun said:

If you like an Easterly gale it’s fab. It will feel very chilly in East Anglia.  The next week looks like being dry and increasingly warm away from North Sea coasts.

As long as the sun continues to shine, I'll be happy...I'll be pulling weeds!

[mushymanrob]

20 hours ago, johnholmes said:

I'll have to disagree mb, the chart you show is GFS synoptic, less reliable than the 500 mb anomaly charts for the 6-14 day time frame. If you look at the 8-14 it still has a noticeable contour ridge along with some +ve heights. Over the years it is almost always a lesser looking ridge where the 6-10 is more marked. Sometimes the 6-10 turns out nearer the mark, and the chart I was trying to show about a week ago (6-10) had a similar ridge to the issue from last evening. Not sure where I posted it but it is somewhere on the site-sorry can't show it.

Anyway whichever of us is nearer the mark no problem, each is entitled to their view. It is only weather anyway, fascinating to follow what the different models suggest may happen even 5 days ahead let alone 10.

Just to add the anomaly NOAA 6-10 first started to suggest an upper ridge around 7 April and has been pretty consistent since.

As expected, im with you on this. However, there is some discrepancy between the 500 mb anomaly charts and the current ops, especially the GFS for this timeframe. The anoms have been suggesting an upper ridge and +ive heights for quite a while now. For several days if not longer (cant recall) these heights have been suggested to our northwest, into the mid north atlantic. The current GFS and ECM isnt far off though, arent IMHO agreeing, with low pressure where the anoms suggest the high should be.

Theres not usually such a big discrepancy, and this leaves a blogger like me all at sea! lol.

 

[Methuselah]

GFS 00Z now seems to have entirely backed away from those wretched, dreich NNE'erlies:

Day 5:       

Day 8:       

Day 11:     

Day 14:     

So, a wee bit of everything in there, folks; and that means no repeat of last-year's Spring-early Summer dust bowl!

[johnholmes]

 

The EC and NOAA are pretty similar in the 6-10 day time frame, this morning it is just the GFS model that shows a different idea with no sign of the ridge and +ve heights in the area of +ve heights with NOAA and EC. It is not often that GFS 500 mb anomaly charts turns out to be more accurate than the other two. This especially so if they have both been consistently similar which they have. I would still back them but perhaps rather than 70-80% with GFS showing a different output, drop it to 60% and comment on the most reliable two but that one is now differing from them?

51 minutes ago, mushymanrob said:

As expected, im with you on this. However, there is some discrepancy between the 500 mb anomaly charts and the current ops, especially the GFS for this timeframe. The anoms have been suggesting an upper ridge and +ive heights for quite a while now. For several days if not longer (cant recall) these heights have been suggested to our northwest, into the mid north atlantic. The current GFS and ECM isnt far off though, arent IMHO agreeing, with low pressure where the anoms suggest the high should be.

Theres not usually such a big discrepancy, and this leaves a blogger like me all at sea! lol.

 

 

[Methuselah]

Wouldn't this just be the perfect recipe for torrential slow-moving thunderstorms?

    

[MATTWOLVES 3]

Plenty of decent weather on offer for next week, and warm at times, especially with shelter... Beyond that the ECM op tends to go much colder, but the mean says your on your own my son.. But there is a gradual cooling beyond next week being highlighted... Long way to go and subject to change though.... Stay safe. 

[Methuselah]

And the GEFS 06Z temperature ensembles don't look too bad, apart from a few days' cack, in the run-up to month's end, that is:

    

[Methuselah]

And the GFS 12Z is, dare I say it, nae bad:

    

    

    

    

    

[damianslaw]

Reliable timeframe, GFS and ECM and UKMO all very similiar, heights locked to our NE, pulling in a stiff easterly wind more so to southern parts, lots of dry often sunny dry weather with temperatures reaching mid-high teens away from eastern coastal parts. One or two favoured spots in sheltered southern and western parts could hit very low 20's. A good spell of weather to come for most, though those on the east coast are going to draw the short straw.

As we approach to latter end to the month (25th onwards), divergence takes place in smaller scale pattern, but overall pattern is the same, heights will retrogress to the NW, thanks to a shift in the northern hemispheric pattern, with a deep trough anchoring down through NE Europe / NW Russia - at the same time heights look like lowering to our SW, so a pincer effect takes place. ECM wants to make less of low height development to our SW, and thus pulls in a cold N/NE feed, GFS wants to make more of atlantic activity to our west, and instead pulls lower heights in from the west/south west - to develop a shallow trough feature over the UK. 

Both are showing a change to something more unsettled before the month's end, and also quite cool.

[Zak M]

The GFS 12z shows high pressure dominating this week, along with above average temperatures

   

Later next week, it turns a bit chillier with temperatures around average as a low moves in, bringing periods of rain

   

And then at the end of April/start of May is shows another high dominating, bringing more settled weather and bringing temps widely into the 20s

   

[Man With Beard]

Very little forcing in the Atlantic by D8

Last time I saw such a slack chart was a week before the 2018 heatwave began. 

No reason to think there'll be a repeat of that - indeed, looks like attacks from the north or west could be on the cards in the days after, but will be watching with interest to see if the Azores High is encouraged to ridge in and bring a plume with it, like the GFS tonight eventually does. 

Edited April 18, 2020 by Man With Beard

[mb018538]

Certainly looking more and more likely that as we get into and beyond next weekend that the weather will finally turn more unsettled. Not looking like a washout by any means, but there will be rain around as pressure finally falls. It’s been a heck of a sunny, warm and dry spell after the deluge of winter though!